Electric seam-welding machine



E. scHRODER ELECTRIC SEAM WELDING MACHINE Filed May 22, 1922 wad?Patented Dec. 9 1924.

UNITED STATE 1,519,0 3 PATENT OFFICE.

EDMUND SC HRCDER, OF BERLIN, GERMANY, ASSIGNOR TO THE FIRM,BRAUN-BRCNING- & 00., F BASEL, SWITZERLAND.

ELECTRIC SEAM-WELDING- MACHINE.

Application filed May 22, 1922. Serial No. 562,757.

a citizen of the German Republic, residing at Berlin, in the Republic ofGermany, have invented a certain new and useful Improved ElectricSeam-Velding Machine;

and 1 do hereby. declare that the following is a full, clear, and exactdescription of the invention, sueh'as will enable others skilled in theart to which it appertains to make and use the same. I

This invention relates to an electric seam welding machine, the distnguishing feature of which resides in the specially advantageousconfiguration of the welding electrode. i

The invention is illustrated, by way of example, in the accompanyingdrawing, in which similar letters denote similar parts throughout theseveral views and in which:

Figure lie at front elevation of the, two cooperating electrodes;

Fi ure 2 is a side view of the same, of which the upper electrode is ofthe novel kind forming the subject matter of this inventio Figure 3 is aview similar to Figure 2 except that the lower electrode is shown insection and somewhat modified in construction;

Figure l is a View corres onding to Figure 3 showing anothermodification of the lower electrode;

Figure 5 is a s'de view. of a complete weldin machine provided with thenovel electrode; 4

Figure (3 is a fragmental detail partly in section of some of theoperating parts of the machine; and,

Figure 7 is a side view of certain elements of the machine. I v

The lower electrode A (Fi s. 1, 2, 5) consists !of a cylindrical mandrewhile the upper electrode consists of a cylindrical body B provided witha thread which is the welding member proper of the latter. Whencommencing the welding operation, the position of the electrode Brelatively to'the electrode A is such that'the extreme point 1 of thethread a lies at the commencement of the line in which the seam weldingoperation will proceed. Supposing, the welding current has been switchedin, the welding operation is effected, first,'at the oint 1, whereuponthe circuit is broken, t e electrode B remaining for a short time in theposition it has occupied during the welding operation. At this time, itis lifted off the electrode A, and rotated so that the point 2 (Fig. 2)gets into the welding line. Now 00 the current is again switched in andthe just ment'oned phases are repeated. This step by step operation iscontinued until the whole seam has been finished. The next welding pointof the electrode, after the point 2, is, of course, the point 3, thenthe point 4, and so onto the other extreme point of the thread a'.

Instead of providing the electrode body 13 with but onev thread, orportion of a (0 thread, as a in Figure 2, it may have two threadportions, indicated at a and a in Figure 3, or three thread portionsindicated at a, a, and a in Figure 4. Corresponding to. the pluralty ofthe thread portions, the stationary lower electrode consists then of twoportions A and A as in Figure 3, or of three poi-tons A, A, and A as inFigure 4.

The form of construction shown in Figures 1 and 2 is intended forcooperation wth a one-phase current, and the other two, (Figures 3 and4) are intended for cooperation with a two-phase current, or athreephase current respectively. The electrode portions A and A, or A, Aand A respectively, are separately connected with the separatephase-wires, and the .thread portions a and a or a, a and arespectively, close the circuit at two or three points which lie inseries with respect to each other. 99 Special sliding contactsconducting the current from stationary parts to movable ones may thus bedispensed with.

The proper succession of the welding phases may be effected in apositive manner, for instance, by the means illustrated in Figures 5, 6and 7, in connection with aonephase current machine, as follows:

0 indicates a driving shaft provided with two cams 5 and 6, of which thefirst serves 100 for switching the current in the proper way, whereasthe other serves for lifting the upper electrode B at the proper timefrom the lower electrode. The cam 6 cooperates with a roll 13 attachedto one arm of a bell-crank 10s lever 18 fulcrumed at 19 in the frontextremity of the head 20 of the machine. The I rear extremity of thehead 20 forms'a id'e 20" for the electrode-holder '21, the guiding stemof which is connected with the bellcrank lever byanother bell-cranklever 22 through the connecting rods 23 and 24. Thus, it is obviousthatthe electrode B will be alternately lifted and lowered by the actionof the cam 6 upon the roll 13. The bell crank lever 18 is provided withan extended arm through which extends a rod 31, and arranged between acollar carried by the rod and the lower face of the arm 30 is a coilspring 32. The lower end of this rod is connected to a foot pedal 33whereby when pressure is applied thereto, the tension of the coil springis increased so that the ioller 13 of the bell-crank lever 18 will beforced against the periphery of the cam 6. Byfso applying pressure tothe roller 13, a more positive actuation of the movable electrode iseffected. I v

The shaft O has secured to it, a cam 9 by which the electrode Bisrotated in steps during these periods in which it is not in contact withthe electrode A. The supporting shaft of the electrode 15 has keyed wita. bevel illustrated in Figure 7.

gear 12 which niesheswitha bevel gear 12 combined with a ratchet-wheel12 which latter cooperates ,with a pawl 11 attached to a rod 10. Thisrod 10 is reciprocated by the cam 9 so that the electrode B is, incertain intervals, correspondingly rotated in steps.

In the Figure 6, the numerals T and 8 designate the bearings of theshaft 0'. The switch actuated by the cam 5 is separately This caln 5osciL late adouble-armed lever 25 having a roller i l-mounted in itsupper end and at its lower end, a contact 16 is arranged which,normally, is pressed against an associate contact 17 by meansof a spiralspring 26. The contacts are separated by the action of the cam 5 uponthe roll 14 during those periods in which the electrode B is lifted offthe electrode A.

'The thread portion (1 consists, or the thread portions a, a, or a, a, arespectively, consist, preferably of a copper bar, or of copper bars, ofquadrangular transverse section which is, or are, inserted into asuitably prov vided groove, or suitably provided grooves, about thecircumference of the electrode B.

Having now described my invention, what I desire to secure by LettersPatent of the United States is:

1. The combination with an electric seam welding machine, a stationaryelectrode, a movable electrode arranged parallel to the stationaryelectrode, means for intermittently lifting the movable electrode fromthe seam of the work piece carried by said statlonary electrode andcausing it to again contact with the seam, and means for interruptingthe welding circuit during themements of the breaks of the contact, of athread disposed about said movable-electrode and forming the weldingmember proper ot' the same. p

2. The combination with an electric seam welding machine, a stationaryelectrode composed of at least two coaxially arranged parts adapted tocooperate with a multiple phase current, a movable electrode arranged inparallelism to the stationary electrode, means my hand.

EDMUND SCHRUDER.

